The use of the word rank for Navy enlisted personnel is incorrect. The term is rate.. The rating badge is a combination of rate (pay grade, as indicated by the chevrons) and rating (occupational specialty, as indicated by the symbol just above the chevrons).
Neurons are nerve cells that are constantly sending signals to your brain, muscles and glands. You have over 100 billion neurons in your brain sending signals. The signals help the different parts of your body communicate with each other.
Those mechanoreceptors send a message along the neuron they are connected to. The neuron connects all the way to the brain, which receives the message that something is touching the body at the precise location of specific mechanoreceptor that sent the message. The brain will act on this information.